In Ubuntu, you may sometimes encounter an error when attempting to run an apt command:

E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable)
E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?


  • Access to a terminal window/command line
  • A user account with sudo or root privileges


  • Verify apt and/or dpkg isn’t running. It’s still running; then, you should wait for the process to finish.
ps aux | grep -i -E 'apt\|dpkg'
  • If the process is stuck using the following.
kill -9 `ps aux | grep -i -E 'apt\|dpkg' | grep -v grep | awk '{print $2}'`
  • Remove the lock file.
sudo rm /var/lib/dpkg/lock
sudo rm /var/lib/apt/lists/lock
sudo rm /var/cache/apt/archives/lock